<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>login</title>
</head>
<body>
<h1>我是网站A，登录页面</h1>

<form method="post">
    <label>用户名：</label><input type="text" name="username" placeholder="请输入用户名"><br/>
    <label>密码：</label><input type="password" name="password" placeholder="请输入密码"><br/>
    <input type="submit" value="登录">
</form>
</body>
</html>